For a given set of browsers what APIs are still considred experimental, and how long have they been experimental?
Below is a list of features that are marked as "Experimental" in Chrome and Firefox
| API | First Browser | Date | Last Browser | Date | Days in experimentation | Notes |
|---|---|---|---|---|---|---|
| html.elements.a.attributionsrc 📋 | Chrome | 5/14/2024 | 810 | |||
| html.elements.a.hreftranslate | Chrome | 4/7/2020 | 2308 | |||
| html.elements.a.target.unfencedTop | Chrome | 7/18/2023 | 1111 | |||
| html.elements.fencedframe 📋 | Chrome | 7/18/2023 | 1111 | |||
| html.elements.fencedframe.allow 📋 | Chrome | 7/18/2023 | 1111 | |||
| html.elements.fencedframe.height 📋 | Chrome | 7/18/2023 | 1111 | |||
| html.elements.fencedframe.width 📋 | Chrome | 7/18/2023 | 1111 | |||
| html.elements.form.autocomplete.webauthn 📋 | Chrome | 11/29/2022 | 1342 | |||
| html.elements.iframe.allow.accelerometer 📋 | Chrome | 4/17/2018 | 3029 | |||
| html.elements.iframe.allow.ambient-light-sensor 📋 | Chrome | 4/17/2018 | 3029 | |||
| html.elements.iframe.allow.attribution-reporting 📋 | Chrome | 9/12/2023 | 1055 | |||
| html.elements.iframe.allow.bluetooth 📋 | Chrome | 8/2/2022 | 1461 | |||
| html.elements.iframe.allow.browsing-topics | Chrome | 7/18/2023 | 1111 | |||
| html.elements.iframe.allow.compute-pressure 📋 | Chrome | 5/14/2024 | 810 | |||
| html.elements.iframe.allow.cross-origin-isolated 📋 | Chrome | 11/17/2020 | 2084 | |||
| html.elements.iframe.allow.document-domain 📋 | Chrome | 1/23/2018 | Firefox | 3/10/2020 | 777 | |
| html.elements.iframe.allow.gamepad 📋 | Firefox | 8/10/2021 | 1818 | Firefox: The default allowlist is * instead of self (as required by the specification).Firefox for Android: The default allowlist is * instead of self (as required by the specification). | ||
| html.elements.iframe.allow.gyroscope 📋 | Chrome | 4/17/2018 | 3029 | |||
| html.elements.iframe.allow.hid 📋 | Chrome | 3/2/2021 | 1979 | |||
| html.elements.iframe.allow.identity-credentials-get 📋 | Chrome | 2/7/2023 | 1272 | |||
| html.elements.iframe.allow.idle-detection 📋 | Chrome | 9/21/2021 | 1776 | |||
| html.elements.iframe.allow.local-fonts 📋 | Chrome | 6/21/2022 | 1503 | |||
| html.elements.iframe.allow.magnetometer 📋 | Chrome | 4/17/2018 | 3029 | |||
| html.elements.iframe.allow.otp-credentials 📋 | Chrome | 8/31/2021 | 1797 | |||
| html.elements.iframe.allow.picture-in-picture 📋 | Chrome | 12/4/2018 | 2798 | |||
| html.elements.iframe.allow.serial 📋 | Chrome | 3/2/2021 | 1979 | |||
| html.elements.iframe.allow.speaker-selection 📋 | Firefox | 8/1/2023 | 1097 | Firefox for Android: Not available due to a limitation in Android (see bug 1473346). | ||
| html.elements.iframe.allow.storage-access 📋 | Chrome | 5/2/2023 | 1188 | |||
| html.elements.iframe.allow.usb 📋 | Chrome | 7/25/2017 | 3295 | |||
| html.elements.iframe.allow.wildcards | Chrome | 11/29/2022 | 1342 | |||
| html.elements.iframe.allow.window-management 📋 | Chrome | 3/29/2022 | 1587 | |||
| html.elements.iframe.allow.xr-spatial-tracking 📋 | Chrome | 12/10/2019 | 2427 | |||
| html.elements.iframe.browsingtopics | Chrome | 7/18/2023 | 1111 | |||
| html.elements.iframe.credentialless 📋 | Chrome | 2/7/2023 | 1272 | |||
| html.elements.iframe.csp 📋 | Chrome | 9/5/2017 | 3253 | |||
| html.elements.img.attributionsrc 📋 | Chrome | 5/14/2024 | 810 | |||
| html.elements.link.rel.expect 📋 | Chrome | 4/16/2024 | 838 | |||
| html.elements.meta.name.application-title | Chrome | 3/4/2025 | 516 | |||
| html.elements.script.attributionsrc 📋 | Chrome | 5/14/2024 | 810 | |||
| html.elements.script.type.importmap.multiple_import_maps 📋 | Chrome | 2/4/2025 | 544 | |||
| html.elements.script.type.speculationrules 📋 | Chrome | 1/10/2023 | 1300 | Chrome: Initial support included same-origin prerendering only.Chrome Android: Initial support included same-origin prerendering only.Edge: Initial support included same-origin prerendering only.Quest Browser: Initial support included same-origin prerendering only.Opera: Initial support included same-origin prerendering only.Opera Android: Initial support included same-origin prerendering only.Samsung Internet: Initial support included same-origin prerendering only. | ||
| html.elements.script.type.speculationrules.eagerness | Chrome | 1/23/2024 | 922 | |||
| html.elements.script.type.speculationrules.expects_no_vary_search | Chrome | 7/23/2024 | 740 | Chrome: Supported for prefetch only.Chrome Android: Supported for prefetch only.Edge: Supported for prefetch only.Opera: Supported for prefetch only.Opera Android: Supported for prefetch only.Samsung Internet: Supported for prefetch only. | ||
| html.elements.script.type.speculationrules.prefetch | Chrome | 2/7/2023 | 1272 | |||
| html.elements.script.type.speculationrules.prerender | Chrome | 9/2/2022 | 1430 | |||
| html.elements.script.type.speculationrules.referrer_policy | Chrome | 3/7/2023 | 1244 | |||
| html.elements.script.type.speculationrules.relative_to | Chrome | 1/23/2024 | 922 | |||
| html.elements.script.type.speculationrules.requires | Chrome | 2/7/2023 | 1272 | |||
| html.elements.script.type.speculationrules.requires.anonymous-client-ip-when-cross-origin | Chrome | 2/7/2023 | 1272 | |||
| html.elements.script.type.speculationrules.source_optional | Chrome | 2/20/2024 | 894 | |||
| html.elements.script.type.speculationrules.urls | Chrome | 1/10/2023 | 1300 | |||
| html.elements.script.type.speculationrules.where | Chrome | 1/23/2024 | 922 | |||
| html.elements.template.shadowrootserializable 📋 | Chrome | 5/14/2024 | 810 | |||
| html.elements.textarea.autocomplete.webauthn 📋 | Chrome | 11/29/2022 | 1342 | |||
| html.global_attributes.hidden.until-found 📋 | Chrome | 5/24/2022 | 1531 | |||
| html.global_attributes.virtualkeyboardpolicy 📋 | Chrome | 9/21/2021 | 1776 | |||
| html.manifest.display_override 📋 | Chrome | 3/2/2021 | 1979 | Chrome: display_override and/or display are required for a web app to be installable.Chrome Android: display_override and/or display are required for a web app to be installable.Edge: display_override and/or display are required for a web app to be installable.Quest Browser: display_override and/or display are required for a web app to be installable.Opera: display_override and/or display are required for a web app to be installable.Opera Android: display_override and/or display are required for a web app to be installable.Samsung Internet: display_override and/or display are required for a web app to be installable. | ||
| html.manifest.display_override.tabbed 📋 | Chrome | 6/11/2024 | 782 | |||
| html.manifest.display_override.window-controls-overlay 📋 | Chrome | 9/2/2022 | 1430 | |||
| html.manifest.file_handlers 📋 | Chrome | 5/24/2022 | 1531 | |||
| html.manifest.launch_handler 📋 | Chrome | 2/7/2023 | 1272 | |||
| html.manifest.launch_handler.client_mode 📋 | Chrome | 2/7/2023 | 1272 | |||
| html.manifest.note_taking 📋 | Chrome | 10/19/2021 | 1748 | |||
| html.manifest.note_taking.new_note_url 📋 | Chrome | 10/19/2021 | 1748 | |||
| html.manifest.protocol_handlers 📋 | Chrome | 11/15/2021 | 1721 | |||
| html.manifest.protocol_handlers.protocol 📋 | Chrome | 11/15/2021 | 1721 | |||
| html.manifest.protocol_handlers.url 📋 | Chrome | 11/15/2021 | 1721 | |||
| html.manifest.serviceworker | Chrome | 10/16/2018 | 2847 | |||
| html.manifest.serviceworker.scope | Chrome | 10/16/2018 | 2847 | |||
| html.manifest.serviceworker.src | Chrome | 10/16/2018 | 2847 | |||
| html.manifest.serviceworker.use_cache | Chrome | 10/16/2018 | 2847 | |||
| html.manifest.share_target 📋 | Chrome | 3/2/2021 | 1979 | Firefox for Android: The property parses, but has no effect. |